Early observations of the gas in galaxy clusters found that it was so dense in the central regions that its cooling time was much shorter than the Hubble time [1]}.
The majority of the clusters studied in the literature show these cool cores [2]}, [3]}. CCs are usually associated to relaxed clusters, since mergers easily erase them. For this reason, it appeared as natural to look for CCs in FGs, in order to confirm their old and dynamically relaxed status.
